DE 199 19 766 A1 and DE 101 36 147 B4 describe photovoltaic power systems such as the photovoltaic power system subject of the Technical Field.
A typical photovoltaic power system includes photovoltaic modules (e.g., solar cells), DC (“direct current”) voltage converters (i.e., DC/DC converters), and an AC (“alternating current”) inverter. Sets of the photovoltaic modules are connected in series and form module strings. Each photovoltaic module converts sunlight into a DC voltage. Each module string generates a combined DC voltage from the DC voltages of the photovoltaic modules in the module string. The module strings provides their combined DC voltages to respective ones of the DC voltage converters. The DC voltage converters match the voltage amplitudes of the combined DC voltages with the AC inverter. The DC voltage converters output the matched combined DC voltages to the AC inverter for transformation by the AC inverter into an AC voltage. The AC voltage from the AC inverter can be fed into the network of a local energy supplier.
Larger photovoltaic power systems include a generator terminal box. Individual connection lines of the module strings are brought in the generator terminal box and connected together with a generator main connection line. The generator main connection line directly leads to an AC inverter. In addition to required connecting terminals, the generator terminal box can include string fuses, string diodes, and/or a string monitoring capability.
Typically, the DC voltage converters are designed either to be subordinate to the module strings (as indicated in DE 101 36 147 B4) or components of the AC inverter (according to the representation of DE 199 19 766 A1). As will be explained with the aid of the drawings that follow, such known arrangements have various drawbacks which are minimized by the present invention.